DOCSLIB.ORG

Chandra Characterization of X-Ray Emission in the Young F-Star Binary System Hd 113766

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chandra Characterization of X-Ray Emission in the Young F-Star Binary System Hd 113766 CHANDRA CHARACTERIZATION OF X-RAY EMISSION IN THE YOUNG F-STAR BINARY SYSTEM HD 113766 The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Lisse, C. M. et al. “CHANDRA CHARACTERIZATION OF X-RAY EMISSION IN THE YOUNG F-STAR BINARY SYSTEM HD 113766.” The Astronomical Journal 153.2 (2017): 62. © 2017 The American Astronomical Society As Published http://dx.doi.org/10.3847/1538-3881/153/2/62 Publisher IOP Publishing Version Final published version Citable link http://hdl.handle.net/1721.1/110119 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The Astronomical Journal, 153:62 (9pp), 2017 February doi:10.3847/1538-3881/153/2/62 © 2017. The American Astronomical Society. All rights reserved. CHANDRA CHARACTERIZATION OF X-RAY EMISSION IN THE YOUNG F-STAR BINARY SYSTEM HD 113766 C. M. Lisse1, D. J. Christian2, S. J. Wolk3, H. M. Günther4, C. H. Chen5, and C. A. Grady6 1 Planetary Exploration Branch, Space Exploration Sector, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA; [email protected] 2 Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, CA 91330, USA; [email protected] 3 Chandra X-ray Center, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA; [email protected] 4 Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, NE83-569, Cambridge, MA 02139, USA; [email protected] 5 STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA; [email protected] 6 Eureka Scientific and Goddard Space Flight Center, Code 667, NASA-GSFC, Greenbelt, MD 20771, USA; [email protected] Received 2016 January 14; revised 2016 September 8; accepted 2016 September 23; published 2017 January 10 ABSTRACT Using Chandra, we have obtained imaging X-ray spectroscopy of the 10–16 Myr old F-star binary HD 113766. We individually resolve the 1 4 separation binary components for the first time in the X-ray and find a total 0.3–2.0 keV luminosity of 2.2×1029 erg s−1, consistent with previous RASS estimates. We find emission from the easternmost, infrared-bright, dusty member HD 113766A to be only ∼10% that of the western, infrared-faint member HD 113766B. There is no evidence for a 3rd late-type stellar or substellar member of HD 113766 with 25 −1 Lx>6×10 erg s within 2′ of the binary pair. The ratio of the two stars’ X-ray luminosity is consistent with their assignments as F2V and F6V by Pecaut et al. The emission is soft for both stars, kTApec=0.30–0.50 keV, suggesting X-rays produced by stellar rotation and/or convection in young dynamos, but not accretion or outflow shocks, which we rule out. A possible 2.8±0.15 (2σ) hr modulation in the HD 113766B X-ray emission is seen, but at very low confidence and of unknown provenance. Stellar wind drag models corresponding to 29 −1 Lx∼2×10 erg s argue for a 1 mm dust particle lifetime around HD 113766B of only ∼90,0000 years, suggesting that dust around HD 113766B is quickly removed, whereas 1 mm sized dust around HD 113766A can survive for >1.5×106 years. At 1028–1029 erg s−1 X-ray luminosity, astrobiologically important effects, like dust warming and X-ray photolytic organic synthesis, are likely for any circumstellar material in the HD 113766 systems. Key words: astrochemistry – protoplanetary disks – planets and satellites: formation – techniques: spectroscopic – X-rays: stars 1. INTRODUCTION evidence for circumstellar dust orbiting the companion, coeval F-star HD 113766B (Meyer et al. 2001), even though studies of We report here on an analysis of Chandra soft X-ray young stellar clusters (e.g., h and χ Persei, Currie observations of HD 113766, a young (10–16 Myr old, et al. 2007, 2008) would have led us to expect a few similar Mamajek et al. 2002; Chen et al. 2006, 2011; Lisse ) dust-forming collisions every Myr in HD 113766B. et al. 2008; Pecaut et al. 2012 , F-star binary stellar system Late F-stars are typically strong X-ray emitters at a young of near-solar metallicity (Fe/H=−0.1, Nordstrom ) +18/ ( age. In fact, the X-ray luminosity function of the Hyades open et al. 2004 , located at a distance of 123 −14 pc 8.16 mas ( ) ( ) ) ( ) cluster age 600 Myr peaks at late F-stars Stern et al. 1995 . Hipparcos parallax from the Earth Van Leeuwen 2007 . Little While X-ray emission of O to mid B-type stars is attributed to is known about this system in the X-ray, other than it is a dissipating shocks in radiation driven winds, and low-mass reported unresolved RASS source of luminosity 2.1 GKM stars have strong convection leading to an αω or a2 +/− × 29 −1 / 0.7 10 erg s . On the other hand, in the optical IR, dynamo, the origin of emission in late B to early F-stars is the system is very interesting. With two component stars of not so clear. While such stars have a convection zone, the nearly identical age characterized by F spectral types in the ratio of the X-ray to bolometric flux is much smaller than in Sco-Cen star-forming association, attention had been called to typical PMS stars. For example, Collins et al. (2009) find this system, since its association with object IRAS 13037–4545 the 10 Myr debris disk host HD 100453 (A9Ve) to have log ( in the IRAS Point Source Catalog was found Backman & LX/Lbol∼−5.9, whereas the typical value for PMS GKM stars Paresce 1993). More recent work by Meyer et al. (2001), Lisse is about −3.5 (Feigelson et al. 2005). Intermediate mass stars et al. (2008), and Chen et al. (2005, 2006, 2011) have also appear to have softer spectra than their lower-mass confirmed that the system exhibits unobscured photospheres brethren. For example, HD 100453 and the similarly aged 51 and that HD 113766A exhibits one of the largest IR flux Eri (F0V) have coronal temperatures of about 0.2 keV, as excesses measured (LIR/L*=0.015), with no detectable H2 opposed to 1–2 keV for similarly aged GKM stars (Feigelson emission. HD 113766A thus belongs to the class of post-T et al. 2006; Collins et al. 2009). Finally, the “FIP-effect” in Tauri objects characterized by young ages of 5–30 Myr, no which elements with first ionization potential below about leftover primordial gas, and large quantities of excess mid-IR 10 eV are observed to be enhanced in abundance by a factor of emission from circumstellar dust. On the other hand, there is no about 3 in the solar corona (Draker et al. 1995), appears to be 1 The Astronomical Journal, 153:62 (9pp), 2017 February Lisse et al. absent in some F-stars such as τ Boo A (an F7V; Maggio over the l0.5 hr of Chandra observation to within the statistical et al. 2011), and Procyon (an F5IV; Raassen et al. 2002 —but photon noise. There are qualitatively, however, potential see Wood & Laming 2013 for a counter example). variations in the HD 113766B light curve, which could be The twin F-stars in the HD 113766 system are thus an periodic. Analyzing the data for possible sinusoidal variations, interesting and useful couple to study. Close enough (separated we find a number of possible solutions with periods ranging by only 1 4, or 170 AU) to be in the same interstellar medium from 2.61–2.92 hr, with a best-fit solution at 2.87 hr, a peak-to- ( ) 2 ISM environment, far enough separated that they minimally peak amplitude of 20%, and c n = 0.98 for 36 degrees of influence each other’s circumstellar environment inside 100 au, freedom (dof). However, we also find a null periodic solution 2 fi and formed at the same time with about the same total mass, with c n = 1.23, and note that the 95% con dence limit of the 2 they are a natural testbed for trying to understand the c n distribution for 36 dof is 1.42. mechanisms of exosystem formation. As Myr-old F-stars can While it is tempting to assign this periodicity to rotationally be expected to be fast rotators, and more convective and X-ray induced variability, the equatorial velocity implied for a 1.35 −1 active than their main-sequence cousins, we would have RSun F6V star is 423 km s , higher than the predicted breakup naively expected both stars to be rapidly rotating, highly speed for a solar abundance F-star (for M*=1.2–1.6 MSun, −1 convective, and X-ray bright. We thus obtained Chandra vbreakup∼300 km s ). The implied equatorial velocity is also observations of HD 113766 in 2010, because: (a) the system approximately a factor of 2 higher than the fastest known stellar contained a well known and well studied IRAS and WISE debris rotators (Głebocki & Gnaciński 2003; Chen et al. 2011). On the disk, while also being a known RASS source, and therefore other hand, Chen et al. (2011) have listed a value of observable by Chandra, which is a rare combination; (b) using v sin i=93 km s−1 for HD 113766B, and Smith et al.
Load more

Recommended publications
  • FY08 Technical Papers by GSMTPO Staff
    AURA/NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation July 23, 2008 Revised as Complete and Submitted December 23, 2008 NGC 660, ~13 Mpc from the Earth, is a peculiar, polar ring galaxy that resulted from two galaxies colliding. It consists of a nearly edge-on disk and a strongly warped outer disk. Image Credit: T.A. Rector/University of Alaska, Anchorage NATIONAL OPTICAL ASTRONOMY OBSERVATORY NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation December 23, 2008 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................................. 1 1 SCIENTIFIC ACTIVITIES AND FINDINGS ..................................................................................... 2 1.1 Cerro Tololo Inter-American Observatory...................................................................................... 2 The Once and Future Supernova η Carinae...................................................................................................... 2 A Stellar Merger and a Missing White Dwarf.................................................................................................. 3 Imaging the COSMOS...................................................................................................................................... 3 The Hubble Constant from a Gravitational Lens.............................................................................................. 4 A New Dwarf Nova in the Period Gap............................................................................................................
    [Show full text]
  • Curriculum Vitae - 24 March 2020
    Dr. Eric E. Mamajek Curriculum Vitae - 24 March 2020 Jet Propulsion Laboratory Phone: (818) 354-2153 4800 Oak Grove Drive FAX: (818) 393-4950 MS 321-162 [email protected] Pasadena, CA 91109-8099 https://science.jpl.nasa.gov/people/Mamajek/ Positions 2020- Discipline Program Manager - Exoplanets, Astro. & Physics Directorate, JPL/Caltech 2016- Deputy Program Chief Scientist, NASA Exoplanet Exploration Program, JPL/Caltech 2017- Professor of Physics & Astronomy (Research), University of Rochester 2016-2017 Visiting Professor, Physics & Astronomy, University of Rochester 2016 Professor, Physics & Astronomy, University of Rochester 2013-2016 Associate Professor, Physics & Astronomy, University of Rochester 2011-2012 Associate Astronomer, NOAO, Cerro Tololo Inter-American Observatory 2008-2013 Assistant Professor, Physics & Astronomy, University of Rochester (on leave 2011-2012) 2004-2008 Clay Postdoctoral Fellow, Harvard-Smithsonian Center for Astrophysics 2000-2004 Graduate Research Assistant, University of Arizona, Astronomy 1999-2000 Graduate Teaching Assistant, University of Arizona, Astronomy 1998-1999 J. William Fulbright Fellow, Australia, ADFA/UNSW School of Physics Languages English (native), Spanish (advanced) Education 2004 Ph.D. The University of Arizona, Astronomy 2001 M.S. The University of Arizona, Astronomy 2000 M.Sc. The University of New South Wales, ADFA, Physics 1998 B.S. The Pennsylvania State University, Astronomy & Astrophysics, Physics 1993 H.S. Bethel Park High School Research Interests Formation and Evolution
    [Show full text]
  • The Twofold Debris Disk Around HD 113766 A⋆
    A&A 551, A134 (2013) Astronomy DOI: 10.1051/0004-6361/201220904 & c ESO 2013 Astrophysics The twofold debris disk around HD 113766 A? Warm and cold dust as seen with VLTI/MIDI and Herschel/PACS J. Olofsson1, Th. Henning1, M. Nielbock1, J.-C. Augereau2, A. Juhàsz3, I. Oliveira4, O. Absil5, and A. Tamanai6 1 Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany e-mail: [email protected] 2 UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG), UMR 5274, Grenoble, France 3 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands 4 Astronomy Department, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259, USA 5 Département d’Astrophysique, Géophysique et Océanographie, Université de Liège, 17 Allée du Six Août, 4000 Sart Tilman, Belgium 6 University Heidelberg, Kirchhoff-Institut für Physik, 69120 Heidelberg, Germany Received 13 December 2012 / Accepted 22 January 2013 ABSTRACT Context. Warm debris disks are a sub-sample of the large population of debris disks, and display excess emission in the mid-infrared. Around solar-type stars, very few objects (∼2% of all debris disks) show emission features in mid-IR spectroscopic observations that are attributed to small, warm silicate dust grains. The origin of this warm dust could be explained either by a recent catastrophic collision between several bodies or by transport from an outer belt similar to the Kuiper belt in the solar system. Aims. We present and analyze new far-IR Herschel/PACS photometric observations, supplemented by new and archival ground-based data in the mid-IR (VLTI/MIDI and VLT/VISIR), for one of these rare systems: the 10–16 Myr old debris disk around HD 113766 A.
    [Show full text]
  • Astro-Ph 2006第2週
    2020年 6月 第2週 新着論文サーベイ 6 月 8 日 (月曜日) [1] arxive:2006.03120 Title: ”Dual-Wavelength ALMA Observations of Dust Rings in Protoplanetary Disks” Author:Feng Long, Paola Pinilla, Gregory J. Herczeg, Sean M. Andrews, Daniel Harsono, Doug Johnstone, Enrico Ragusa, Ilaria Pascucci, David J. Wilner, Nathan Hendler, Jeff Jennings, Yao Liu, Giuseppe Lodato, Francois Menard, Gerrit van de Plas, Giovanni Dipierro Comments: accepted for publication in ApJ Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR) [観測/ALMA] 原始惑星系円盤中にリング状の構造を持つDS Tau, GO Tau, DL Tau を 、ALMA で 観 測 し た 。波 長1.3 は mm と 2.9 mm の 2 バ ン ド で 、角 分 解 能 は と も0.1 に秒 角 。2 バ ン ド で リ ン グ の 端 の 位 置 は 同 じ で あ っ た 。こ の こ と を 、ダ ス ト 進化のモデルで説明した。 [2] arxive:2006.03113 Title: ”The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation” Author:J. L. Ortiz, P. Santos-Sanz, B. Sicardy, G. Benedetti-Rossi, D. Bérard, N. Morales, R. Duffard, F. Braga-Ribas, U. Hopp, C. Ries, V. Nascim- beni, F. Marzari, V. Granata, A. Pál, C. Kiss, T. Pribulla, R. Komžík, K. Hornoch, P. Pravec, P. Bacci, M. Maestripieri, L. Nerli, L. Mazzei, M. Bachini, F. Martinelli, G. Succi, F. Ciabattari, H. Mikuz, A. Carbog- nani, B. Gaehrken, S. Mottola, S. Hellmic, F. L. Rommel, E. Fernández- Valenzuela, A. Campo Bagatin, S. Cikota, A.
    [Show full text]
  • Presence and Role of Sub-Micron Grains in Debris Discs P
    A&A 626, A24 (2019) Astronomy https://doi.org/10.1051/0004-6361/201935341 & © P. Thebault and Q. Kral 2019 Astrophysics Is there more than meets the eye? Presence and role of sub-micron grains in debris discs P. Thebault and Q. Kral LESIA – Observatoire de Paris, UPMC Université Paris 06, Université Paris-Diderot, Paris, France e-mail: [email protected] Received 22 February 2019 / Accepted 10 April 2019 ABSTRACT Context. The presence of sub-micron grains has been inferred in several debris discs, usually because of a blue colour of the spectrum in scattered light or a pronounced silicate band around 10 µm, even though these particles should be blown out by stellar radiation pressure on very short timescales. So far, no fully satisfying explanation has been found for this apparent paradox. Aims. We investigate the possibility that the observed abundances of sub-micron grains could be naturally produced in bright debris discs, where the high collisional activity produces them at a rate high enough to partially compensate for their rapid removal. We also investigate to what extent this potential presence of small grains can affect our understanding of some debris disc characteristics. Methods. We used a numerical collisional code to follow the collisional evolution of a debris disc down to sub-micron grains far below the limiting blow-out size sblow. We considered compact astrosilicates and explored different configurations: A and G stars, cold and warm discs, bright and very bright systems. We then produced synthetic spectra and spectral energy distributions, where we identified and quantified the signature of unbound sub-micron grains.
    [Show full text]
  • PDF, on the Incidence of Wise Infrared Excess Among Solar
    The Astrophysical Journal, 837:15 (11pp), 2017 March 1 doi:10.3847/1538-4357/837/1/15 © 2017. The American Astronomical Society. All rights reserved. On the Incidence of Wise Infrared Excess Among Solar Analog, Twin, and Sibling Stars A. D. Da Costa1, B. L. Canto Martins1, I. C. Leão2, J. E. Lima Jr1, D. Freire da Silva1, D. B. de Freitas3, and J. R. De Medeiros1 1 Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN, 59072-970, Brazil; dgerson@fisica.ufrn.br 2 European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching, Germany 3 Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-900, Fortaleza, Ceará, Brazil Received 2016 April 25; revised 2016 November 3; accepted 2016 November 6; published 2017 February 27 Abstract This study presents a search for infrared (IR) excess in the 3.4, 4.6, 12, and 22 μm bands in a sample of 216 targets, composed of solar sibling, twin, and analog stars observed by the Wide-field Infrared Survey Explorer (WISE) mission. In general, an IR excess suggests the existence of warm dust around a star. We detected 12 μm and/or 22 μm excesses at the 3σ level of confidence in five solar analog stars, corresponding to a frequency of 4.1% of the entire sample of solar analogs analyzed, and in one out of 29 solar sibling candidates, confirming previous studies. The estimation of the dust properties shows that the sources with IR excesses possess circumstellar material with temperatures that, within the uncertainties, are similar to that of the material found in the asteroid belt in our solar system.
    [Show full text]
  • Propiedades F´Isicas De Estrellas Con Exoplanetas Y Anillos Circunestelares Por Carlos Saffe
    Propiedades F´ısicas de Estrellas con Exoplanetas y Anillos Circunestelares por Carlos Saffe Presentado ante la Facultad de Matem´atica, Astronom´ıa y F´ısica como parte de los requerimientos para la obtenci´on del grado de Doctor en Astronom´ıa de la UNIVERSIDAD NACIONAL DE CORDOBA´ Marzo de 2008 c FaMAF - UNC 2008 Directora: Dr. Mercedes G´omez A Mariel, a Juancito y a Ramoncito. Resumen En este trabajo, estudiamos diferentes aspectos de las estrellas con exoplanetas (EH, \Exoplanet Host stars") y de las estrellas de tipo Vega, a fin de comparar ambos gru- pos y analizar la posible diferenciaci´on con respecto a otras estrellas de la vecindad solar. Inicialmente, compilamos la fotometr´ıa optica´ e infrarroja (IR) de un grupo de 61 estrellas con exoplanetas detectados por la t´ecnica Doppler, y construimos las dis- tribuciones espectrales de energ´ıa de estos objetos. Utilizamos varias cantidades para analizar la existencia de excesos IR de emisi´on, con respecto a los niveles fotosf´ericos normales. En particular, el criterio de Mannings & Barlow (1998) es verificado por 19-23 % (6-7 de 31) de las estrellas EH con clase de luminosidad V, y por 20 % (6 de 30) de las estrellas EH evolucionadas. Esta emisi´on se supone que es producida por la presencia de polvo en discos circunestelares. Sin embargo, en vista de la pobre resoluci´on espacial y problemas de confusi´on de IRAS, se requiere mayor resoluci´on y sensibilidad para confirmar la naturaleza circunestelar de las emisiones detectadas. Tambi´en comparamos las propiedades de polarizaci´on.
    [Show full text]
  • Infrared Spectra of Dust Around Other Stars Show Mineralogical Features Diagnostic of Their Composition
    Infrared Spectroscopy of Extraterrestrial Materials William T. Reach, Universities Space Research Association, SOFIA Associate Director for Science Mehmet Yesiltas, University of Central Florida, graduate student George Rossman, California Institute of Technology, Professor of Mineralogy HD 113766 HD 172555 Infrared spectra of dust around other stars show mineralogical features diagnostic of their composition. This infrared spectrum of dust around a white dwarf star shows prominent silicate emission features diagnostic of tits composition. Two astronomical spectra of debris around main sequence stars, as analyzed by C. Lisse et al. (2008, 2009 ApJ). HD 113766 debris was ascribed to material similar to an S-type asteroid We measured infrared spectra of meteorites of all classes, in order to form a comparison Terrestrial Craters, Tektites database for understanding how material Some natural but single-mineral specimens Asteroidal around other stars compares to debris in the were measured for comparison. Solar System. Minerals Cometary Lunar Some carbonaceous chondrite meteorites have a near-infrared feature from water of hydration. We have attempted to remove the water by heating but it remains present at 200 C and is likely from the parent body. And now, a bit of publicity for the project that takes most of my time. Water of Hydration SOFIA update Formation of Stars Galaxies and the Plans: We are writing a paper describing Interstellar Medium Planetary Science and Planets Galactic Center Two special issues of SOFIA papers have the survey observations, and we will follow been published, one in Astrophysical Journal for mid-infrared imaging with up two findings using specially-selected FORCAST, the other in Astronomy and Astrophysics for submm spectroscopy samples recently approved by the Meteorite with GREAT.
    [Show full text]
  • THE STAR FORMATION NEWSLETTER an Electronic Publication Dedicated to Early Stellar Evolution and Molecular Clouds
    THE STAR FORMATION NEWSLETTER An electronic publication dedicated to early stellar evolution and molecular clouds No. 145 — 15 November 2004 Editor: Bo Reipurth ([email protected]) Abstracts of recently accepted papers Molecular Evolution in Collapsing Prestellar Cores III: Contraction of A Bonnor-Ebert Sphere Yuri Aikawa1, Eric Herbst2, Helen Roberts2,3, and Paola Caselli4 1 Department of Earth and Planetary Sciences, Kobe University, Kobe 657-8501, Japan 2 Departments of Physics, Chemistry, and Astronomy, The Ohio State University, Columbus, OH 43210, USA 3 Department of Physics, UMIST, PO Box 88, Manchester M60 1QD, UK 4 INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze, Italy E-mail contact: [email protected] The gravitational collapse of a spherical cloud core is investigated by numerical calculations. The initial conditions of the core lie close to the critical Bonnor-Ebert sphere with a central density of ∼ 104 cm−3 in one model (α = 1.1), while gravity overwhelms pressure in the other (α = 4.0), where α is the internal gravity-to-pressure ratio. The α = 1.1 model shows reasonable agreement with the observed velocity field in prestellar cores. Molecular distributions in cores are calculated by solving a chemical reaction network that includes both gas-phase and grain-surface reactions. When the central density of the core reaches 105 cm−3, carbon-bearing species are significantly depleted in the central region of the α = 1.1 model, while the depletion is only marginal in the other model. The two different approaches encompass the observed variations of molecular distributions in different prestellar cores, suggesting that molecular distributions + can be probes of contraction or accumulation time scales of cores.
    [Show full text]
  • Publication List (25 June 2015)
    Prof. Dr. Th. Henning, Max Planck Institute for Astronomy, Heidelberg Publication list (25 June 2015) Papers in refereed journals 1. Henning, Th.: The Analytical Calculation of the Second Spherical Exponential In- tegral, Astron. Nachr. 303 (1982), 125-126. 2. Henning, Th.: A Model of the 10 Micrometer Silicate Feature in the Spectra of BN-like IR-Point Sources, Astron. Nachr. 303 (1982), 117-124. 3. Henning, Th., G¨urtler,J., Dorschner, J.: Observationally-Based Infrared Efficiencies and Planck Means for Circumstellar Dust Grains, Astr. Space Sci. 94 (1983), 333- 349. 4. Henning, Th.: The Nature of the 10 and 20 Micrometer Features in Circumstellar Dust Shells, Astr. Space Sci. 97 (1983), 405-419. 5. Henning, Th., Friedemann, C., G¨urtler,J., Dorschner, J.: A Catalogue of Extremely Young Massive and Compact Infrared Objects, Astron. Nachr. 305 (1984), 67-78. 6. Henning, Th.: Parameters of Very Young and Massive Stars with Dust Shells, Astr. Space Sci. 114 (1985), 401-411. 7. G¨urtler,J., Henning, Th., Dorschner, J., Friedemann, C.: On the Properties of Very Young Massive Infrared Sources, Astron. Nachr. 306 (1985), 311-327. 8. Henning, Th., Svatos, J.: Stability of Amorphous Circumstellar Silicate Grains, Astron. Nachr. 307 (1986), 49-52. 9. Henning, Th.: Mass Loss from Very Young Massive Stars, Astron. Nachr. 307 (1986), 119-127. 10. Dorschner, J., Friedemann, C., G¨urtler,J., Henning, Th., Wagner, H.: Amorphous Bronzite { A Silicate of Astronomical Importance, MNRAS 218 (1986), 37-40. 11. Henning, Th., G¨urtler,J.: BN Objects { A Class of Very Young and Massive Stars, Astr. Space Sci.
    [Show full text]
  • Circumstellar Dust Created by Terrestrial Planet Formation in HD 113766
    Circumstellar Dust Created by Terrestrial Planet Formation in HD 113766 C. M. Lisse1, C. H. Chen2, M. C. Wyatt3, and A. Morlok4 Submitted to the Astrophysical Journal, 10 April 2007; Accepted 07 September 2007 1 Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 [email protected] 2NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 [email protected] 3Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK [email protected] 4Department of Earth and Planetary Sciences, Faculty of Science, Kobe University, Nada, Kobe 657-8501, Japan [email protected] 46 Pages, 7 Figures, 3 Tables Key Words: astrochemistry; infrared: stars; radiation mechanisms: thermal; techniques: spectroscopic; stars: planetary systems: formation, protoplanetary disks 1 Proposed Running Title: Terrestrial Planet Dust Around HD 113766A Please address all future correspondence, reviews, proofs, etc. to: Dr. Carey M. Lisse Planetary Exploration Group, Space Department Johns Hopkins University, Applied Physics Laboratory 11100 Johns Hopkins Rd Laurel, MD 20723 240-228-0535 (office) / 240-228-8939 (fax) [email protected] 2 ABSTRACT We present an analysis of the gas-poor circumstellar material in the HD 113766 binary system (F3/F5, ~16Myr), recently observed by the Spitzer Space Telescope. For our study we have used the infrared mineralogical model derived from observations of the Deep Impact experiment. We find the dust dominated by warm, fine (~1 um) particles, abundant in Mg-rich olivine, crystalline pyroxenes, amorphous silicates, Fe-rich sulfides, amorphous carbon, and colder water-ice. The warm dust material mix is akin to an inner main belt asteroid of S-type composition.
    [Show full text]
  • Evolution of Circumstellar Disks Around Normal Stars: Placing Our Solar System in Context
    Evolution of Circumstellar Disks Around Normal Stars: Placing Our Solar System in Context Michael R. Meyer The University of Arizona Dana E. Backman SOFIA/SETI Institute Alycia J. Weinberger Carnegie Institution of Washington Mark C. Wyatt University of Cambridge Over the past 10 years abundant evidence has emerged that many (if not all) stars are born with circumstellar disks. Understanding the evolution of post–accretion disks can provide strong constraints on theories of planet formation and evolution. In this review, we focus on developments in understanding: a) the evolution of the gas and dust content of circumstellar disks based on observational surveys, highlighting new results from the Spitzer Space Telescope; b) the physical properties of specific systems as a means to interpret the survey results; c) theoretical models used to explain the observations; d) an evolutionary model of our own solar system for comparison to the observations of debris disks around other stars; and e) how these new results impact our assessment of whether systems like our own are common or rare compared to the ensemble of normal stars in the disk of the Milky Way. 1. Introduction from spectral energy distributions (SEDs) and/or resolved disk morphology? Is there any connection between debris At the original Protostars and Planets conference in disks and the radial velocity planets? Is there evidence for 1978, the existence of circumstellar disks around sun–like differences in disk evolution as a function of stellar mass? stars was in doubt, with most researchers preferring the In answering these questions, our objective is no less hypothesis that young stellar objects were surrounding by than to understand the formation and evolution of planetary spherical shells of material unlike the solar nebula thought systems through observations of the gas and dust content to give rise to the solar system (Rydgren et al., 1978).
    [Show full text]